1. Field of the Invention
The present invention relates to an interchangeable, adjustable support or mount for an optical alignment device such as a firearm sight and a method for removeably mounting optical devices such as gun sights on pistols or other firearms.
2. Discussion of the Prior Art
At present, a wide variety of optical sights are available for use on firearms such as pistols.
A typical handgun or pistol has optical alignment fixtures or sights including a front sight and a rear sight which are aligned with one another to form a sight picture for aligning the pistol's point of aim on the target. Prior art pistol sights are usually mounted along the top edge of the pistol. Traditional semi-automatic pistols (such as the well known Colt™ model 1911, caliber 45) include a grip or handle carrying a lower receiver and a trigger mechanism and a slide member is slidably supported on the lower receiver.
The traditional front sight is a vertically projecting blade or ramp-like member mounted at the front of the slide and the rear sight is adapted for mounting to the rear of the slide using a dovetailed transverse protrusion that mates with a corresponding transverse dovetailed slot in the slide.
Police officers and members of the military require especially rugged sights on their weapons and so a genre of firearms and accessories adapted for “combat carry” has evolved to serve their special needs.
Fixed sights are intended to provide a smooth and snag-free draw, a clear sight picture and rugged service; the fixed sight shown in Design Pat. D447,205 is one example. Others, including Wayne Novak, have also developed a number of designs for sights intended to provide rugged service, and such sights are often fitted in a transverse dovetailed notch having standardized dimensions known in the industry as the “Novak Notch” dimensions. By “transverse” is meant in a direction at a right angle to the pistol bore's central axis and lying in a horizontal plane when the pistol is held in a standard grip with the bore central axis in a horizontal plane. Generally, the standardized dimensions for the notch will accept a dovetail-like projection that is 12.5 millimeters (mm) in fore-aft length on a planar bottom surface and tapers inwardly at 70 degrees from horizontal on front and back wall surfaces; the bottom planar surface of the projection is preferably 3 mm in vertical height from the upper surface of the notch opening, within customary gunsmithing tolerances.
While the combat sights of the prior art do provide a smooth and snag-free draw, a clear sight picture and rugged service, they often do not provide a wide enough range of adjustability and are not readily changed with other sights, since sights are often installed by gunsmiths using specialized tools.
Those removable sight mounts of the prior art have proven unsuitable because they do not maintain the point of aim of “zero” when removed and re-installed.
Pistol sights are often used in a variety of situations. A sight is customarily optically aligned along the axis of the bore and used to align the bore of the firearm with the target. Target sights are usually adjustable in the left and right direction for “windage” and in the up and down direction for “elevation.” Usually, a shooter will mount a sight to a firearm and then immediately “zero” the sight by a procedure of adjusting windage and elevation settings so that the sight's point of aim corresponds with the point of impact for a selected target at a desired range.
If a sight is mounted to a large caliber firearm generating large recoil forces, the zero may change after firing several rounds and the sight must then be adjusted for proper zero again. Traditional combat carry sights, as described above, are usually not adjustable for windage, and so shooters have turned to permanently altering the front sight pose by filing it down (to raise the point of impact) or substituting taller front sight blades (to lower the point of impact). Adjustments for windage have required the shooter to strike the side of the sight with a pin punch and hammer, to force the sight laterally in the notch, a procedure which does not permit fine adjustment.
There has been a long felt need, then, for a method and apparatus permitting attachment and adjustment of a combat carry style rear sight or the like on a firearm such as a pistol, permitting the shooter to quickly and easily zero the sights and permitting the user to change to different sights in an interchangeable manner.